Electrochemical oxidative [4 + 2] annulation of tertiary anilines and alkenes for the synthesis of tetrahydroquinolines

2018 ◽  
Vol 20 (21) ◽  
pp. 4870-4874 ◽  
Author(s):  
Pengfei Huang ◽  
Pan Wang ◽  
Shengchun Wang ◽  
Shan Tang ◽  
Aiwen Lei
Keyword(s):  
Heterocyclic Compounds ◽  
Nitrogen Heterocycles

Heterocyclic compounds, especially nitrogen heterocycles, are one of the most important classes of compounds in the pharmaceutical and agrochemical industries.

scholarly journals Polyhalonitrobutadienes as Versatile Building Blocks for the Biotargeted Synthesis of Substituted N-Heterocyclic Compounds

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2863 ◽  
Author(s):  
Viktor A. Zapol’skii ◽  
Ursula Bilitewski ◽  
Sören R. Kupiec ◽  
Isabell Ramming ◽  
Dieter E. Kaufmann
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Heterocyclic Compounds ◽  
Nitrogen Heterocycles ◽  
Building Blocks ◽  
Antibacterial Activities ◽  
Synthetic Approach ◽  
Selective Synthesis ◽  
Ic50 Values ◽  
Thiophene Derivatives

Substituted nitrogen heterocycles are structural key units in many important pharmaceuticals. A new synthetic approach towards heterocyclic compounds displaying antibacterial activity against Staphylococcus aureus or cytotoxic activity has been developed. The selective synthesis of a series of 64 new N-heterocycles from the three nitrobutadienes 2-nitroperchloro-1,3-butadiene, 4-bromotetrachloro-2-nitro-1,3-butadiene and (Z)-1,1,4-trichloro-2,4-dinitrobuta-1,3-diene proved feasible. Their reactions with N-, O- and S-nucleophiles provide rapid access to push-pull substituted benzoxazolines, benzimidazolines, imidazolidines, thiazolidinones, pyrazoles, pyrimidines, pyridopyrimidines, benzoquinolines, isothiazoles, dihydroisoxazoles, and thiophenes with unique substitution patterns. Antibacterial activities of 64 synthesized compounds were examined. Additionally, seven compounds (thiazolidinone, nitropyrimidine, indole, pyridopyrimidine, and thiophene derivatives) exhibited a significant cytotoxicity with IC50-values from 1.05 to 20.1 µM. In conclusion, it was demonstrated that polyhalonitrobutadienes have an interesting potential as structural backbones for a variety of highly functionalized, pharmaceutically active heterocycles.

Iron-catalyzed radical cascade 6-endo cyclization of dienes towards fused nitrogen heterocycles initiated by an alkoxycarbonyl radical

2020 ◽  
Vol 18 (36) ◽  
pp. 7086-7089
Author(s):  
Shanshan Qiao ◽  
Peng-Cheng Qian ◽  
Fan Chen ◽  
Jiang Cheng
Keyword(s):  
Heterocyclic Compounds ◽  
Nitrogen Heterocycles ◽  
Reaction Conditions ◽  
Cascade Cyclization ◽  
Radical Cascade ◽  
Nitrogen Heterocyclic

An iron-catalyzed radical cascade cyclization of dienes initiated by an alkoxycarbonyl radical has been developed in the presence of (NH4)2S2O8, leading to a series of fused nitrogen heterocyclic compounds under relatively mild reaction conditions.

Divergent Synthesis of Five-Membered Nitrogen Heterocycles via Cascade Reactions of 4-Arylfuroxans

Synthesis ◽  
2020 ◽  
Vol 52 (18) ◽  
pp. 2667-2678
Author(s):  
Leonid L. Fershtat ◽  
Daniil A. Chaplygin ◽  
Ivan V. Ananyev ◽  
Nina N. Makhova
Keyword(s):  
Ring Opening ◽  
Heterocyclic Compounds ◽  
Nitrogen Heterocycles ◽  
Cascade Reactions ◽  
Materials Chemistry ◽  
One Pot ◽  
Mild Conditions ◽  
Novel Method ◽  
High Yields

A novel method for the synthesis of a diverse series of functionally substituted five-membered heterocyclic compounds via atom-economic, regio-, and diastereoselective one-pot reaction cascade was developed. This approach involves a ring opening in 4-arylfuroxans to α-oximinoarylacetonitrile oxides followed by [3+2] cycloaddition to various dipolarophiles to afford multisubstituted isoxazoles and isoxazolines. Subsequent azole–azole rearrangement of (oximino)isoxazolines/-isoxazoles, which can be conducted in a one-pot manner, results into functionally substituted furazans formation. The developed protocol is operationally simple, proceeds in mild conditions and with high yields of target heterocyclic systems. Overall, this study represents a new mode of isoxazole and 1,2,5-oxadiazole functionalization strategy, which is useful in medicinal and materials chemistry.

Heterocyclic compounds from alloxan and amines. X. Amine purpurates

1970 ◽  
Vol 23 (2) ◽  
pp. 323 ◽  
Author(s):  
JW Clark-Lewis ◽  
K Moody
Keyword(s):  
Carbon Dioxide ◽  
Acetic Acid ◽  
Nitrogen Atom ◽  
Heterocyclic Compounds ◽  
Nitrogen Heterocycles ◽  
Heterocyclic Amine ◽  
Reaction Conditions

Secondary and tertiary alicyclic amines (piperidine, morpholine, N-ethyl-piperidine, and N-methylmorpholine), and aromatic nitrogen heterocycles (benzimidazole, 2-methyl- and 2-t-butyl-benzimidazole, and pyridine), are shown to yield the heterocyclic amine purpurates (murexide analogues) by reaction with anhydrous alloxan in dry acetic acid. The central nitrogen atom of the purpurate anion, normally derived from ammonia, is considered to arise from degradation of some of the alloxan, and is accompanied by liberation of carbon dioxide. Pyrrolidine did not yield a purpurate (or carbon dioxide) under the reaction conditions.

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